• 제목/요약/키워드: pH dependent

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Farm to abattoir conditions, animal factors and their subsequent effects on cattle behavioural responses and beef quality - A review

  • Njisane, Yonela Zifikile;Muchenje, Voster
    • Asian-Australasian Journal of Animal Sciences
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    • 제30권6호
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    • pp.755-764
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    • 2017
  • The current review seeks to highlight the concerns that have been raised on pre-slaughter stress, contributing factors and its consequent effects on cattle behavioural responses and the quality of beef; inter-linking the activities involved from birth to slaughter. Such information is crucial in light of the consumer concerns on overall animal welfare, quality of meat and food security. Slaughter animals are exposed to different conditions during production and transportation to abattoirs on a daily basis. However; the majority of studies that have been done previously singled out different environments in the meat production chain, while conclusions have been made that the welfare of slaughter animals and the quality of meat harvested from them is dependent on the whole chain. Behaviour is a critical component used to evaluate the animals' wellbeing and it has been reported to have an effect on product quality. Apart from the influence of on-farm, transportation and abattoir conditions, the genetic background of the animal also affects how it perceives and responds to certain encounters. Stress activates the animals' hypothalamic-pituitary-adrenal activity, triggering release of various stress hormones such as catecholamines and cortisol, thus glycogen depletion prior slaughter, elevated ultimate pH and poor muscle-meat conversion. Pre-slaughter stress sometimes results to cattle attaining bruises, resulting to the affected parts of the carcass being trimmed and condemned for human consumption, downgrading of the carcass and thus profit losses.

Static behavior of a laterally loaded guardrail post in sloping ground by LS-DYNA

  • Woo, Kwang S.;Lee, Dong W.;Yang, Seung H.;Ahn, Jae S.
    • Geomechanics and Engineering
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    • 제15권5호
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    • pp.1101-1111
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    • 2018
  • This study aims to present accurate soil modeling and validation of a single roadside guardrail post as well as a single concrete pile installed near cut slopes or compacted sloping embankment. The conventional Winkler's elastic spring model and p-y curve approach for horizontal ground cannot directly be applied to sloping ground where ultimate soil resistance is significantly dependent on ground inclination. In this study, both grid-based 3-D FE model and particle-based SPH (smoothed particle hydrodynamics) model available in LS-DYNA have been adopted to predict the static behavior of a laterally loaded guardrail post. The SPH model has potential to eliminate any artificial soil stiffness due to the deterioration of the node-connected Lagrangian soil mesh. For this purpose, this study comprises two parts. Firstly, only 3-D FE modeling has been tested to show the numerical validity for a single concrete pile in sloping ground using Mohr-Coulomb material. However, this material option cannot be implemented for SPH elements. Nevertheless, Mohr-Coulomb model has been used since this material model requires six input soil data that can be obtained from the comparative papers in literatures. Secondly, this work is extended to compute the lateral resistance of a guardrail post located near the slope using the hybrid approach that combines Lagrange FE elements and SPH elements by the suitable node-merging option provided by LS-DYNA. For this analysis, the FHWA soil material developed for application to road-base soils has been used and also allows the application of SPH element.

대두와 쥐눈이콩의 비배당체 이소플라본 함량에 대한 인공위액과 소화효소 처리효과 (Effects of Artificial Stomach Fluid and Digestive Enzymes on the Aglycone Isoflavone Contents of Soybean and Black Bean (Rhynchosia Molubilis : Yak-Kong))

  • 강순아;장기효;조윤희;홍경희;서지혜;조여원
    • Journal of Nutrition and Health
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    • 제36권1호
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    • pp.32-39
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    • 2003
  • Phytoestrogens, especially soy-derived isoflavones, are receiving great scrutiny as a food supplement for preventing hormone dependent disease such as postmenopausal osteoporosis. Their beneficial effects are derived from aglycone form of isoflavones, such as daidzein, genistein or glycitein. In contrast to the common usage of soybean, black bean (Rhynchosia Molubilis : Yak-kong) has been used as a supplement for preventing postmenopausal osteoporosis in oriental medicine. To investigate the effects of the saliva, artificial stomach fluid, and digestive enzymes on the conversion of glycosidic isoflavone to aglycone form, soybean and black bean were extracted with 70% methanol and freeze-dried. The recovery yield of methanol extracts of black bean was 14.1% which was higher than that of soybean, 13.5%. In terms of total isoflavones, we routinely obtained larger amount of isoflavones from black bean than those from soybean. By incubating methanol extracts of soybean and black bean with IN HCI for 180 min, the proportions of aglycones relative to the total isoflavone were significantly increased (32.4% and 52.4%, respectively). In vitro conversion, digestive enzymes ($\beta$-glucosidase and $\alpha$-glucosidase) may hydrolyze glycosidic bond of isoflavone more effectively than saliva or artificial stomach fluid did. It seems to say that the activity of $\beta$-glucosidase was higher than those of $\alpha$-glucosidase. The rate of conversion of glucoside form to aglycone form in black bean and soybean was low in physiological condition (pH) tested, although the enzymatic hydrolysis of glucoside was active. These results demonstrated that the composition of aglycone in food may be the important factors in terms of the bioavailability of isoflavones. (Korean J Nutrition 36(1): 32-39, 2003)

Chemical Modification of Bovine Brain Succinic Semialdehyde Reductase by Diethylpyrocarbonate

  • Lee, Byung-Ryong;Jeon, Seong-Gyu;Bahn, Jae-Hoon;Choi, Kyung-Soon;Yoon, Byung-Hak;Ahn, Yoon-Kyung;Choi, Eun-A;Lee, Kil-Soo;Cho, Sung-Woo;Choi, Soo-Young
    • BMB Reports
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    • 제32권3호
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    • pp.254-258
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    • 1999
  • The NADPH-dependent succinic semialdehyde reductase is one of the key enzymes in the brain GABA shunt, and it catalyzes the formation of the neuromodulator $\gamma$-hydroxybutyrate from succinic semi aldehyde. This enzyme was inactivated by diethylpyrocarbonate (DEP) with the second-order rate constant of $1.1{\times}10^3\;M^{-1}min^{-1}$ at pH 7.0, $25^{\circ}C$, showing a concomitant increase in absorbance at 242 nm due to the formation of N-carbethoxyhistidyl derivatives. Complete inactivation of succinic semialdehyde reductase required the modification of five histidyl residues per molecule of enzyme. However, only one residue was calculated to be essential for enzyme activity by a statistical analysis of the residual enzyme activity. The inactivation of the enzyme by DEP was prevented by preincubation of the enzyme with the coenzyme NADPH but not with the substrate succinic semialdehyde. These results suggest that an essential histidyl residue involved in the catalytic activity is located at or near the coenzyme binding site of the brain succinic semialdehyde reductase.

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추출 용매에 따른 산딸기 추출물의 항산화 및 항균 활성 (Antioxidant and Antimicrobial Properties of Various Solvent Extracts from Robus idaeus)

  • 이미희;이정은
    • 한국식품영양학회지
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    • 제28권5호
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    • pp.774-781
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    • 2015
  • The objective of the present study was to determine the total phenol and flavonoid contents and to evaluate the antioxidant potential, of different solvent extracts (ethyl acetate, n-butanol, chloroform, and water) from Robus idaeus in various radical scavenging models (DPPH activity, superoxide dismutase (SOD) activity, reducing power, and nitrite scavenging activity), along with their antimicrobial potential. Measurement of total phenol and flavonoid content of the ethyl acetate extract of R. idaeus was found to be significantly higher than those of the other extracts. The ethyl acetate extract (at a concentration of $1,000{\mu}g/mL$) showed significantly higher reducing power and DPPH radical scavenging activity as compared to the other extracts. Results were dose-dependent. Moreover, the ethyl acetate extract of R. idaeus ($1,000{\mu}g/mL$) showed potent antioxidant efficacy ($85.5{\pm}1.18%$) as evidenced by nitrite scavenging ability at pH 1.2. All solvent extracts of R. idaeus showed lower SOD-like activity (13.72~20.54%). In addition, the antimicrobial activity of all solvent extracts except water extract showed strong inhibition (inhibitory zones in mm) of Staphylococcus aureus ($19.40{\pm}1.00mm$) and Bacillus cereus ($20.50{\pm}0.21mm$) growth. In particular, ethyl acetate extracts (100 mg/mL) showed antimicrobial activity comparable to that of tetracycline (0.01 mg/mL), which was used as a positive control. The results of this study indicate that the ethyl acetate extract of R. idaeus is a natural antioxidant and antimicrobial, with enriched phenols and flavonoids concentration, that has potential in the development of health-enhancing food products.

허혈심근 Xanthine Oxidase 의 전환에 관한 연구 (Conversion of Myocardial Xanthine Oxidase in Ischemic Heart of Rat)

  • 박창권
    • Journal of Chest Surgery
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    • 제21권5호
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    • pp.803-815
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    • 1988
  • The present experiments were performed to confirm the hypothesis that xanthine oxidase[XOD], as a source and mechanism of oxygen radical production, plays an important role in the genesis of the reperfusion injury of ischemic myocardium. The experimental ischemic-reperfusion injury was induced in isolated, Langendorff preparations of rat hearts by 60 min. Of global ischemia with aortic clamping followed by 20 min. of reperfusion with oxygenated Krebs-Henseleit solution[pH 7.4, 37*C]. The results were as follows: 1. The releases of creatine phosphokinase and a lipid peroxidation product, malondialdehyde[MDA] into the coronary effluent were abruptly increased upon reperfusion of ischemic hearts. The increases of the enzyme and MDA were suppressed significantly in the hearts removed from rats pretreated with allopurinol, a specific XOD inhibitor[20mg/kg, oral, 24 hrs and 2 hrs before study]. This effect of allopurinol was comparable to that of oxygen radical scavengers, superoxide dismutase[5, 000U] and catalase[12, 500 U]. 2. The increased SOD-inhibitable reduction of ferricytochrome C, which was infused to the hearts starting with reperfusion, was significantly suppressed in allopurinol pretreated hearts. 3. Activities of myocardial XOD were compared in the normal control hearts and the ischemic ones. Total enzyme activities were not different in both hearts. However, comparing with the control, the ischemic ones showed higher activity in 0-form and lower activities in D-form and D/O-form. 4. In the ischemic hearts, phenylmethylsulfonyl fluoride, a serine protease inhibitor, prevented significantly the increase of 0-form and the decreases of D and D/O-form, while thiol reagents did not affect the changes of the enzyme. 5. The increase of 0-form and the decreases of D and D/0-form were not significant in both calcium-free perfused and pimozide, a calmodulin inhibitor, treated ischemic hearts. 6. The SOD-inhibitable reduction of ferricytochrome C were suppressed by PMSF and pimozide treatment as well as by calcium-free perfusion. It is suggested from these results that in the ischemic rat myocardium, xanthine oxidase is converted to oxygen radical producing 0-form by calcium, calmodulin-dependent proteolysis and plays a contributing role in the genesis of ischemic-reperfusion injury by producing oxygen free radicals.

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마이크로웨이브법에 의해 제조된 HAp 및 BCP 분말이 뼈모세포 및 파골세포의 활성에 미치는 영향 (The Effects of HAp and BCP Nano Powders Synthesized by Microwave-Assisted Synthesis on the Activation of Osteoblast and Osteoclast)

  • 송호연;민영기;양훈모;맹주양
    • 한국재료학회지
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    • 제17권12호
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    • pp.669-675
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    • 2007
  • Hydroxyapatite (HAp) and biphasic calcium phosphate (BCP) nano powders were synthesized using the microwave-assisted synthesis process dependent on pH and microwave irradiation time. The average size of a powder was less than 100 nm in diameter. Through in-vitro cytotoxicity tests by an extract dilution method, the HAp and BCP nano powders have shown to be cytocompatible for L-929 fibroblast cells, osteoblastlike MG-63 cells and osteoclast-like Raw 264.7 cells. The activation of osteoblast was estimated by alkaline phosphatase (ALP) activity. When the HAp and BCP were treated to MG-63 cells, alkaline phosphatase activities increased on day 3, compared with those of the untreated cells. Also, the collagen fibers increased when the HAp and BCP powders suspension were treated to MG-63 cells, compared to those of the untreated cells. Quantitative alizarin red S mineralization assays showed a trend toward increasing mineralization in osteoblast cultured with powder suspension. In conclusion, hydroxyapatite and biphasic calcium phosphate appeared to be a bone graft substitute material with optimal biocompatibility and could be further applied to clinical use as an artificial bone graft substitute.

흡수촉진제인 지방산염이 토끼의 비강점막 균질액에서 인슐린 분해에 미치는 영향 (Effect of Fatty Acid Salts on Proteolysis of Insulin in the Nasal Tissue Homogenates of Rabbits)

  • 한건;차철희;정연복;박정숙
    • Journal of Pharmaceutical Investigation
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    • 제22권2호
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    • pp.97-104
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    • 1992
  • The purpose of this study was (i) to determine whether protease inhibition by medium chain fatty acids such as sodium caprate, sodium caprylate and sodium laurate led to suppression of insulin proteolysis over a range of insulin concentrations and (ii) elucidate preventing effect of the enhancers on molecular self-association of insulin in pH 7.4 phosphate buffer isotonic solution. To this end, the rate of insulin proteolysis in nasal tissue supernatants of the albino rabbits was determined in the presence of $0.1{\sim}2%$ sodium caprylate, sodium caprate and sodium laurate at insulin concentrations ranging from $5\;to\;100\;{\mu}M$. At fatty acid salts concentration lower than 0.5%, insulin proteolysis was accelerated but the enhancers of high concentration (>1%) reduced the rate of insulin proteolysis. These effects were dependent upon insulin concentration and chain length of fatty acid salts. Circular dichroism spectra of insulin solutions were then determined. Monomer fraction of insulin was increased with increasing sodium caprate. Therefore, half-life decrease of insulin at low concentrations of the enhancers was attributed to deaggregation of insulin by the enhancers, increasing the proportion of monomers available for nasal proteolysis. And the increase of half-life at high concentration of the enhancers was attributed to inhibitory effect on protease rather than the effect of monomer fraction.

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The Leaching Behavior of Unirradiated $UO_2$ Pellets in Wet Storage and Disposal Conditions

  • Park, Geun-Il;Lee, Hoo-Kun
    • Nuclear Engineering and Technology
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    • 제28권4호
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    • pp.349-358
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    • 1996
  • The leaching behavior of uranium from unirradiated CANDU UO$_2$ fuel pellet in the spent fuel wet storage and disposal conditions has been investigated. A modified IAEA leach test method was used, and then the extent of leaching was monitored by analysis for uranium in the leachant. The leach test has been performed in various leachants(demineralized water and boric acid solution at pH=6, synthetic granite groundwater) for a long-term period of 5.4 years, and the effect of temperature on the leach rate of uranium has been analyzed. The leach rates of uranium at $25^{\circ}C$ were dependent on the leachants. Over initial 100 days of leach periods, the leach rate in groundwater was the highest in three leachants and no significant differences of leach rates ore observed in the demineralized oater and boric acid solution. But these leach rates in three leachants around 2,000 days at $25^{\circ}C$ appeared to be reached the steady rates in the range of 1~5$\times$10$^{-8}$ g/$\textrm{cm}^2$ day. The leach rate of uranium in groundwater shooed to be independent of the temperature, but those in both demineralized water and boric acid solution increased with temperature. These results show that the leaching behavior of uranium from UO$_2$ fuel in both the demineralized water ann boric acid may be controlled tv the surface oxidative.dissolution reaction of UO$_2$ and the leach rate of uranium in groundwater at room temperature could mainly be controlled by the complex reaction of dissolved uranyl ions with carbonate ions and no variation of leach rate of UO$_2$ in groundwater with temperature may be due to the local deposition of passivating uranyl phases on the surface.

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Inhibition of a Neutral Form of Sphingomyelinase by Alkylthioureido-l,3-propandiols, KY353X Series

  • Jung, Sang-Mi;Jeong, Eui-Man;Jo, Dong-Hwawn;Chin, Mi-Reyoung;Jun, Hyung-Jin;Kim, Yong-Hyun;Jeon, Hyung-Jun;Lee, Dong-Hun;Park, Mi-Ja;Oh, Mi-Jung;Yim, Chul-Bu;Kim, Dae-Kyong
    • Biomolecules & Therapeutics
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    • 제11권3호
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    • pp.169-173
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    • 2003
  • Alkylthioureido-1,3-propandiols (KY353X series) were synthesized and evaluated as inhibitors for neutral sphingomyelinase (N-SMase). To examine whether KY353X series inhibit N-SMase, we purified the N-SMase from bovine brain. The N-SMase was partially purified by sequential chromatographies of DEAE-Cellulose anionic exchange and phenyl-5PW hydrophobic HPLC. These seqeuntial procedures for N-SMase resulted in a 67-fold purification and excluded other isoforms of SMase. Based on in vitro assay, KY353X series inhibited N-SMase activity in time, concentration-dependent manners and completely inactivated N-SMase at 50 $\mu$M. In particular, KY3535 and KY3536 inhibited more effectively than the others. To further determine the .inhibitory pattern, a Dixon plot was constructed, to showing that the inhibition by KY3535 and KY3536 were competitive. The inhibition constant (Ki) of KY3535 and KY3536 was 1.7 $\mu$M and 2.5$\mu$M in 100 mM Tris-HCl buffer, pH 7.0, respectively.